Salmonella in the Laying Hen

Quantitative estimation of the impact of setting a new target for the reduction of Salmonella in breeding hens of Gallus gallus

“…The same serovars were administered vaginally, and again S. Enteritidis was recovered more frequently, and in higher numbers, than the other Salmonellae from spleen, ovary, oviduct and egg contents, although on this occasion S. Typhimurium also contaminated eggs (Okamura et al, 2001b). Serovars S. Typhimurium, S. Senftenberg and S. Thompson appeared to be poor internal colonisers of eggs in an oral inoculation study (Cox et al, 1973). However, a view that S. Enteritidis is simply a better systemic coloniser of hens than other serovars, and consequently tends to be deposited more often in forming eggs, is not supported by certain other evidence and much depends on the characteristics of the individual strains chosen for such experiments and their physiological state after storage.…”

“…On the other hand, experimental inoculations in laying hens by a variety of routes, including intravenous, conjunctival, cloacal and vaginal, have resulted in detectable Salmonella in the ovaries and the oviduct, providing routes for in vivo contamination of yolk and albumen, respectively (Cox et al, 1973;Cox et al, 2000;Gantois et al, 2008;Miyamoto et al, 1997;Okamura et al, 2001a;Okamura et al, 2001b). However, relatively few Salmonella serovars appear to be able to consistently infect eggs laid by these experimentally inoculated hens, suggesting that there are other critical factors determining an invasive Salmonella strain's potential for internal egg contamination (Berchieri et al, 2001;Keller et al, 1997).…”

Rcent literature on detection of salmonellae in poultry production flocks: A critical review

“…In 23 flocks, there was evidence of infection, and 10 serotypes were isolated. Cox et al (1973) found positive salmonella isolations in 25% of the faecal samples from experimentally infected laying hens. Fagerberg et al (1976) cultured for salmonellae faecal samples collected on paper for monitoring specimens from experimental poultry-holding facilities before bird infection and also following infection.…”

“…Cox et al (1973) were unable to isolate salmonellae from the body tissues of adult laying hens that were experimentally infected orally with salmonellae. The contents of the intestinal tract are frequently used for detecting salmonellosis in avian species.…”

“…For procedures to be effective, as many eggs as possible should be cultured. In culturing egg shells and egg contents from experimentally infected laying hens, Cox et al (1973) isolated very few salmonellae. Hobbs (1963) discussed in detail techniques for the isolation of salmonella organisms from eggs and egg products.…”